An Analysis of Under-Insulated Houses in the Existing Canadian Housing Stock

Executive Summary

Canada’s existing housing stock is composed of approximately 8 million dwellings which range in vintage from nearly new to a few hundred years in age. Likewise, their energy performance and associated Greenhouse Gas Emissions vary dramatically with some existing houses displaying performance levels exceeding those of contemporary structures while others contain barely any insulation, airtightness measures or modern mechanical systems.

The project described in this report was initiated by NAIMA Canada to calculate the potential benefits of selective improvements to insulation levels in Canada’s existing housing stock. Using energy audit data, supplied by Natural Resources Canada, from approximately 634,000 houses, estimates were made of the number of “under-insulated” houses in each province and territory, as well as the six largest cities.

In addition, a detailed analysis was conducted to estimate the quantity of thermal insulation which would be required to upgrade the existing housing stock to levels approaching (although not equal to) contemporary standards. The metric used to express the quantity of required insulation was the “Retrofit Potential” (RP), defined as the area of a building component to be insulated multiplied by the R-value necessary to upgrade it to the appropriate level. The Retrofit Potential’s units are ft2 • R (and the metric equivalent m2 • RSI). The RP was calculated for five, major building components: ceilings with attics, ceilings without attics, exterior walls, basement walls and basement headers.

Finally, estimates were made of the energy savings and reductions in Greenhouse Gas Emissions which would be achieved if the full Retrofit Potential were realized.